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问题 选择题

在pH =1的无色溶液中，能大量共存的是：

A．Al3+、Na+、NO3-、Cl-

B．Cu2+、Na+、NO3-、Cl-

C．Ba2+、K+、CO32-、MnO4-

D．NH4+、H+、CH3COO-、 OH-

答案

答案：A

Cu2+和MnO4－均是有色离子，BC不符合题意。D中H＋和CH3COO－及 OH－均不能大量共存，因此答案是A。

填空题


A Sports体育运动
Many animals engage in play，but homo sapiens is the only animal (1) have invented sports.Since sports are an invention，a part of culture (2) than an aspect of nature，all definitions of sports are somewhat arbitrary. (3) sports are a human universal found in every known culture or a (4) unique to modern society depends upon one’s definition of sports.Men and (5) have always run，jumped，climbed，lifted，thrown， and wrestled，but they have (6) always performed these physical activities competitively. Although all literate societies seem to (7) contests of one sort or another in which men， and sometimes women， (8) in displays and tests of physical skill and prowess，sports may be (9) defined as physical contests performed for their own sake and not for (10) ulterior end.According to this strict definition，neither Neolithic hunters nor contestants (11) religious ceremonies such as the ancient Olympic Games were engaged in sports. (12) on the stipulation that sports must be performed for their own sake (13) the paradoxical elimination of many activities which are usually thought of as (14) ，such as exercises done for the sake of cardiovascular fitness，races run (15) satisfy a physical education requirement，ball games played to earn a paycheck. (16) definition also means abandonment of the traditional usage in which"sport，"derived (17) Middle English disporter，refers to any light hearted recreational activity.In the. (18) of some 18th- century aristocrats，a game of backgammon and the seduction of (19) milkmaid were both considered good sport，but this usage of the term (20) become archaic.

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单项选择题

慢性肝炎的原因不包括:

A．甲型肝炎

B．乙型肝炎

C．丙型肝炎

D．丁型肝炎

E．自身免疫性肝炎
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